Elastomeric Monoalkenyl Arene-Conjugated Diene Block Copolymers

Abstract

A styrene-isoprene block copolymer that includes at least two polymerized styrene blocks alternating with at least one polymerized isoprene block and has a spin bonding temperature that is below its degradation temperature.

1 . A block copolymer containing alternating blocks of polymerized monoalkenyl arene and polymerized isoprene, the block copolymer having at least two polymerized monoalkenyl arene blocks, a melt flow rate, as determined by ASTM D 1238 (200° C., 5 kilogram weight), of at more than 40 decigrams per minute, a minimum capillary spinning temperature that is less than or equal to its degradation temperature that exceeds its spin bonding temperature by at least one degree centigrade, and a viscosity at the minimum capillary spinning temperature of no more than 1500 poise (150 pascal seconds).  
     
     
         2 . The block copolymer of  claim 1 , wherein the monoalkenyl arene is styrene.  
     
     
         3 . The block copolymer of  claim 2 , wherein the block copolymer is a styrene-isoprene-styrene triblock copolymer that has a styrene content within a range of from 10 percent by weight to less than 40 percent by weight, based upon block copolymer weight, both ends of the range being included within the range.  
     
     
         4 . (canceled)  
     
     
         5 . (canceled)  
     
     
         6 . The block copolymer of  claim 3 , wherein the styrene content is less than 35 percent by weight, based on block copolymer weight.  
     
     
         7 . The block copolymer of  claim 3 , wherein the styrene content is greater than 14 percent by weight, based on block copolymer weight.  
     
     
         8 . (canceled)  
     
     
         9 . The block copolymer of  claim 1 , wherein the block copolymer is a styrene-isoprene-styrene-isoprene-styrene pentablock copolymer that has a styrene content within a range of from 10 to 50 percent by weight, based on block copolymer weight.  
     
     
         10 . The block copolymer of  claim 6 , wherein the styrene content is less than 45 weight percent, based on block copolymer weight.  
     
     
         11 . The block copolymer of  claim 6 , wherein the styrene content is at least 15 percent by weight, based on block copolymer weight.  
     
     
         12 . The block copolymer of  claim 1 , wherein the minimum capillary spinning temperature is less than or equal to 230° centigrade.  
     
     
         13 . (canceled)  
     
     
         14 . The block copolymer of  claim 1 , wherein the minimum capillary spinning temperature is within a range of from 130° centigrade to 229° centigrade.  
     
     
         15 . The block copolymer of  claim 3 , wherein the block copolymer has a molecular weight within a range of from 50,000 to 90,000, both ends of the range being included within the range.  
     
     
         16 . (canceled)  
     
     
         17 . The block copolymer of  claim 6 , wherein the block copolymer has a molecular weight that falls within a range of from 70,000 to 200,000, both ends of the range being included within the range.  
     
     
         18 . (canceled)  
     
     
         19 . The block copolymer of  claim 3 , wherein the melt flow rate is less than 5000 decigrams per minute.  
     
     
         20 . (canceled)  
     
     
         21 . The block copolymer of  claim 3 , wherein the viscosity at spin bonding temperature falls within a range of from 200 centipoises (20 pascal seconds) to 1500 centipoises (150 pascal seconds), both ends of the range being included in the range.  
     
     
         22 . The block copolymer of  claim 6 , wherein the viscosity at spin bonding temperature falls within a range of from 200 centipoises (20 pascal seconds) to 1000 centipoises (100 pascal seconds), both ends of the range being included in the range.  
     
     
         23 . The block copolymer of  claim 1 , wherein the block copolymer is selected from the group consisting of styrene-isoprene-styrene-isoprene tetrablock copolymers, styrene-isoprene-styrene-isoprene-styrene-isoprene hexablock copolymers, and styrene-isoprene block copolymers having at least four styrene blocks and at least three isoprene blocks.  
     
     
         24 . The block copolymer of  claim 16 , wherein the block copolymer contains no more than 7 styrene blocks and no more than 5 isoprene blocks.  
     
     
         25 . A polymer blend composition comprising the block copolymer of  claim 1  in combination with a polymer selected from the group consisting of polyolefins (for example)), polystyrene, thermoplastic polyurethanes, polycarbonates, polyamides, polyethers, poly/vinyl chloride polymers, poly/vinylidene chloride polymers, and polyester polymers.  
     
     
         26 . The polymer blend composition of  claim 18 , wherein the polymer is a polyolefin selected from the group consisting of ethylene/styrene interpolymers, ethylene-alpha olefin interpolymers where the alpha-olefin includes 3 or more carbon atoms, polypropylene, an enhanced polypropylene polymer, a homogeneously branched ethylene polymer, a substantially linear ethylene interpolymer, a polyolefin elastomer or a polyolefin plastomer.